In addition, Littlewood-Paley theory and the real theory of Hardy spaces in harmonic analysis, turned out to be a simple and powerful tool in solving wave map equation, Navier-Stkoes equation and Euler equation [18, 27, 47, 48, 49, 58, 59].

• 此外调和分析中的Littlewood-Paley理论，Hardy空间的实变理论，对波映照方程，Euler方程，Navier-Stokes方程的求解提供了简单而有力的工具[18，27，47，48，49，60，61]。